“Sinusitis” refers to inflammation of one or more nasal sinus cavities, which are moist, hollow spaces in the bones of the skull. Sinusitis affects millions of people each year. According to the National Ambulatory Medical Care Survey (NAMCS), approximately 14% of adults report having at least one yearly episode of sinusitis. Further, sinusitis is believed to be one of the top five most common diagnoses for which antibiotics are prescribed.
There are four pairs of sinuses: frontal, maxillary, ethmoid, and sphenoid. The sinuses are located behind the eyebrows, cheekbones, and nose. The sinuses help moisten and warm air that is filtered by the nose, serving to protect the lungs. The sinus cavities, nose, and lungs are lined with mucous membranes, which protect the airways by trapping irritants that are inhaled. Tiny hair-like filaments called cilia are in constant movement and sweep mucus and the trapped irritants out of the airways and nasal passages. In each of the sinuses, the mucus drains out of a tiny opening called the ostium.
The ostium of any sinus cavity can get plugged. When this blockage prevents the flow of mucus, the pressure builds up, leading to sinusitis typified by inflammation and pain. If the blocked sinus becomes infected with bacteria, the sinus becomes even more inflamed and painful. Symptoms of sinusitis can include, among other things, facial pain or pressure, discolored mucus, a diminished sense of smell, cough, headache, bad breath, fever, toothache, pressure in the ears and fatigue.